The representation of SetCard model now changed in how it stores a symbol - we store a presentation independent id of the symbol using int rather than the NSString. But we still support #contents method which returns a partial string representation of the card (e.g. no coloring)
SetCard is now displayed in three different shading versions - open, solid and shaded. We use stroke width and color to emulate this. Shaded version is filled with light gray inside of the symbol.